Infectivity of liposomally encapsulated nucleic acids isolated from EMC virus and scrapie-infected mouse brain.

The ability of liposomes to enhance nucleic acid infectivity in vivo was studied. Encephalomyocarditis (EMC) virus RNA was extracted and encapsulated within liposomes. The infectivity of EMC RNA was increased by liposomal entrapment after intraperitoneal injection of mice, but decreased after intracerebral injection. In contrast, when nucleic acids from scrapie-infected brains were entrapped in liposomes and injected into mice by one of four routes, no cases of scrapie were observed. This is the first report of the enhancement of nucleic acid infectivity by liposomes in vivo.